grc20 source pure

1const (
2	MaxNameLen   = 64
3	MaxSymbolLen = 11
4	MaxDecimals  = 18
5)

1const (
2	MintEvent     = "Mint"
3	BurnEvent     = "Burn"
4	TransferEvent = "Transfer"
5	ApprovalEvent = "Approval"
6)

 1var (
 2	ErrInsufficientBalance   = errors.New("insufficient balance")
 3	ErrInsufficientAllowance = errors.New("insufficient allowance")
 4	ErrInvalidAddress        = errors.New("invalid address")
 5	ErrCannotTransferToSelf  = errors.New("cannot send transfer to self")
 6	ErrReadonly              = errors.New("banker is readonly")
 7	ErrRestrictedTokenOwner  = errors.New("restricted to bank owner")
 8	ErrMintOverflow          = errors.New("mint overflow")
 9	ErrInvalidAmount         = errors.New("invalid amount")
10	ErrSpoofedRealm          = errors.New("rlm does not match the current crossing frame")
11	ErrNotRealm              = errors.New("rlm must be a realm (got EOA/origin)")
12	ErrInvalidName           = errors.New("invalid token name (empty, too long, or contains control chars)")
13	ErrInvalidSymbol         = errors.New("invalid token symbol (empty, too long, or contains chars outside [A-Za-z0-9_-])")
14	ErrInvalidDecimals       = errors.New("invalid decimals (must be 0..18)")
15)

1func IsCanonicalTeller(t Teller) bool

1func NewToken(name, symbol string, decimals int, id seqid.ID, rlm realm) (*Token, *PrivateLedger)

 1type PrivateLedger struct {
 2	// Total supply of the token managed by this ledger.
 3	totalSupply int64
 4	// chain.Address -> int64
 5	balances avl.Tree
 6	// owner.(chain.Address)+":"+spender.(chain.Address)) -> int64
 7	allowances avl.Tree
 8	// Pointer to the associated Token struct
 9	token *Token
10}

 1type Teller interface {
 2	// Returns the name of the token.
 3	GetName() string
 4
 5	// Returns the symbol of the token, usually a shorter version of the
 6	// name.
 7	GetSymbol() string
 8
 9	// Returns the decimals places of the token.
10	GetDecimals() int
11
12	// Returns the amount of tokens in existence.
13	TotalSupply() int64
14
15	// Returns the amount of tokens owned by `account`.
16	BalanceOf(account address) int64
17
18	// Moves `amount` tokens from the caller's account to `to`. rlm must
19	// be the caller's own captured cur — verified via rlm.IsCurrent().
20	//
21	// Returns an error if the operation failed.
22	Transfer(_ int, rlm realm, to address, amount int64) error
23
24	// Returns the remaining number of tokens that `spender` will be
25	// allowed to spend on behalf of `owner` through {transferFrom}. This is
26	// zero by default.
27	//
28	// This value changes when {approve} or {transferFrom} are called.
29	Allowance(owner, spender address) int64
30
31	// Sets `amount` as the allowance of `spender` over the caller's tokens.
32	//
33	// Returns an error if the operation failed.
34	//
35	// IMPORTANT: Beware that changing an allowance with this method brings
36	// the risk that someone may use both the old and the new allowance by
37	// unfortunate transaction ordering. One possible solution to mitigate
38	// this race condition is to first reduce the spender's allowance to 0
39	// and set the desired value afterwards:
40	// https://github.com/ethereum/EIPs/issues/20#issuecomment-263524729
41	Approve(_ int, rlm realm, spender address, amount int64) error
42
43	// Moves `amount` tokens from `from` to `to` using the
44	// allowance mechanism. `amount` is then deducted from the caller's
45	// allowance.
46	//
47	// Returns an error if the operation failed.
48	TransferFrom(_ int, rlm realm, from, to address, amount int64) error
49}

 1type Token struct {
 2	// Identifier precomputed in NewToken to make ID() a cheap field read.
 3	id string
 4	// Name of the token (e.g., "Dummy Token").
 5	name string
 6	// Symbol of the token (e.g., "DUMMY").
 7	symbol string
 8	// Number of decimal places used for the token's precision.
 9	decimals int
10	// Pointer to the PrivateLedger that manages balances and allowances.
11	ledger *PrivateLedger
12}